On July 5, 1993, at 1930 central daylight time, a Piper PA-28-235, N8633W, registered to Charles W. Legan of Ulysses, Kansas, and operated by a private rated pilot, experienced a loss of engine power and conducted a forced landing in a field near Bloom, Kansas. The airplane sustained substantial damage on impact with the terrain. The pilot reported no injuries. The personal flight was being conducted under provisions of 14 CFR Part 91 in visual meteorological conditions. No flight plan was on file. The flight departed Liberal, Kansas, at 1830, with the intended destination of Ulysses, Kansas. The pilot indicated in his written statement that he felt that the mixture control arm contributed to the accident. A post accident examination revealed that the nose landing gear had collapsed during impact with the terrain and had damaged the mixture cable. A written statement by a mechanic who examined the airplane is attached to this report. The mechanic found no mechanical anomalies; however, he stated that the fuel in the tanks appeared to be a mix of av-gas and automotive fuel. He described the fuel as being free of contamination; however, "had a cloudy, milky white appearance."